Flutemetamol [18F] Injection is a diagnostic positron emission tomography (PET) agent for the imaging of β-amyloid plaques in the brain. The synthesis of the agent can be performed using automated synthesis platforms with or without using specially-tailored cassettes. For example, the synthesis can be performed using either the TRACERlab FX F-N platform or the FASTlab™ platform, commercially available from GE Healthcare a division of General Electric Company in conjunction with auxiliary preparative high pressure liquid chromatography equipment. After synthesis, the bulk agent is transferred to high pressure liquid chromatography (HPLC) equipment to separate the physico-chemically similar compounds [18F]flutemetamol from its deprotected precursor, AH111832 (6-hydroxy-2-(4′-(N-methyl)amino-3′-nitro)phenylbenzothiazole) and hence obtain purified [18F]flutemetamol.
However there still exists a need in the art for alternative purification methods for the preparation of [18F]flutemetamol. The invention as described below answers such a need. Specifically, Applicants have now found a process that eliminates the use of preparative HPLC equipment.